1. Field of the Invention
This invention relates to liquid spraying devices and, more particularly, to such devices capable of operating as self-contained units.
2. Description of the Prior Art
With the advent of so-called aerosol sprayers, it has become customary for individual consumers to utilize a variety of liquids prepackaged in such units for spraying. Such units are commonly in sizes approximating 6, 11 or 14 ounces net weight of a liquid to be sprayed and a suitable propellant such as Freon. The contents are under low pressure which is supposed to be maintained at an effective level by the propellant throughout the useful life of the unit. A readily operable finger valve is used to release the contents. A wide variety of materials are marketed in aerosol spray containers, including paints, household cleaners, hair sprays and other beauty aids, fire extinguishers, insecticides, lubricants and degreasers, to name a few. The units are not refillable, but are designed to be discarded when used up.
Numerous problems exist with respect to these common aerosol sprayers. Valves frequently malfunction and may clog so that the entire contents of the container cannot be used or they may stick in the open position so that the contents are released when they are not needed to be used. Loss of propellant may occur so that the contents cannot be released. They are hazardous in that they may explode if exposed to heat in excess of 120.degree. F. and may cause serious damage if punctured. Some scientists contend that the ozone layer protecting the earth from bombardment by cosmic rays and other radiation may be damaged or destroyed by the accumulation of aerosol propellants discharged into the atmosphere. Other deleterious effects may result from the release of aerosol propellants in a confined space occupied by humans or simply by the inhalation of the propellant gas into the lungs during use.
In addition, considerable economic waste is involved in the system of aerosol use. The containers are not recyclable insofar as is known and they frequently are discarded by careless users in ways that litter the landscape. The metals and other materials used in the containers are not recycled. According to information at hand, more than half of the listed net weight contents of an aerosol container comprises the propellant and less than half is made up by the material which is to be sprayed. Also, more than half of the cost of the contents is due to the cost of the propellant contained therein; this is without regard to the the cost of the container involved. Thus, the cost of the actual material used by the purchaser of an aerosol sprayer is a relatively small fraction of the purchase price of the aerosol can and contents.
In view of the numerous drawbacks involved in the use of aerosol spray containers, and particularly as a result of the present increased concern upon the effects of the use of such devices on our environment, efforts are being made to market many of the materials formerly packaged in aerosols in other forms of containers with various types of applicators. A common approach has been to provide the liquid in a container with a small finger-operated pump contained therein. However, these are not universally effective and they certainly lack the convenience of the aerosol spray device. There is obviously a need for a device which can spray with the effectiveness of an aerosol sprayer (when it is working properly) in a safe and harmless manner without the various drawbacks of the aerosol sprayer. Such a device should have a self-contained propellant with the capability of emitting a spray comparable to that available from the aerosol. Preferably, the device should be readily manufacturable from low cost materials and should be reliable in operation. It should be refillable with bulk materials available at low cost. It should be easily pressurizable with a harmless and readily available propellant.
The present invention meets these requirements.